The moment of 0 acceleration does not occur inside the cannon. The question is asking how far he'll travel after being shot, before his acceleration becomes 0. You need to determine when that occurs. Hint: what forces act on him during flight?

The moment of 0 acceleration does not occur inside the cannon. The question is asking how far he'll travel after being shot, before his acceleration becomes 0. You need to determine when that occurs. Hint: what forces act on him during flight?

No, actually, I asked my professor and he just told me it was a trick question and he wanted to know INSIDE the cannon, not after the guy is shot from the cannon and the acceleration is 0.